| /* |
| * Copyright 2009-2010 by The Regents of the University of California |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * you may obtain a copy of the License from |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package edu.uci.ics.hyracks.algebricks.core.algebra.runtime.aggregators; |
| |
| import java.io.DataOutput; |
| import java.io.IOException; |
| |
| import edu.uci.ics.hyracks.algebricks.core.algebra.runtime.base.IRunningAggregateFunction; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.runtime.base.IRunningAggregateFunctionFactory; |
| import edu.uci.ics.hyracks.algebricks.core.api.exceptions.AlgebricksException; |
| import edu.uci.ics.hyracks.dataflow.common.data.accessors.IDataOutputProvider; |
| import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference; |
| |
| public class TupleCountRunningAggregateFunctionFactory implements IRunningAggregateFunctionFactory { |
| |
| private static final long serialVersionUID = 1L; |
| |
| @Override |
| public IRunningAggregateFunction createRunningAggregateFunction(IDataOutputProvider provider) |
| throws AlgebricksException { |
| |
| final DataOutput out = provider.getDataOutput(); |
| |
| return new IRunningAggregateFunction() { |
| |
| int cnt; |
| |
| @Override |
| public void step(IFrameTupleReference tuple) throws AlgebricksException { |
| ++cnt; |
| try { |
| out.writeInt(cnt); |
| } catch (IOException e) { |
| throw new AlgebricksException(e); |
| } |
| } |
| |
| @Override |
| public void init() throws AlgebricksException { |
| cnt = 0; |
| } |
| }; |
| } |
| |
| } |